The present invention relates in general to monitoring/vision systems for motor vehicles, and, more specifically, to a camera system having a fixed image sensor and a movable reflective element for providing various fields of view beneath a vehicle while providing environmental shielding.
The use of vision and other remote sensing systems on vehicles, together with object detection, image processing, and driver assistance functionality, has increased rapidly in modern vehicle designs (e.g., in blind spot monitoring, lane detection, adaptive cruise control, impact warning, and others). In another example, parking assist systems and backup systems are known for providing images and/or warning signals to a driver to aid in the steering/alignment process and to avoid impacts with obstacles.
Image sensors and other remote sensors are typically mounted to a side surface (e.g., grille or hatchback) or roof structures where exposure to the road environment such as dirt, mud, and salt is manageable. A camera/image sensor is typically not mounted to an underside of the vehicle because of the difficulty of keeping a lens clear of debris. Without a view from the underside, however, these driver assist systems are less useful for avoiding contact of the wheels or lower fascia with adjacent objects (especially when a driver is starting from a stationary position). For better assistance during parking or other low speed maneuvers, it would be desirable to provide a better view of the vicinity of the wheels.
Prior attempts to utilize cameras providing a view beneath a vehicle include the use of retractable covers and telescoping camera mounts so that a camera can be deployed when needed and then stowed within a protected chamber during normal vehicle travel. The use of a movable camera, however, introduces additional costs and additional sources of potential device failures as compared with a fixed camera. In addition, since the camera lens is deployed into the challenging environment beneath the vehicle it is still subject to contamination with debris. Clearing the debris from a camera lens may be more difficult than from other, less sensitive surfaces.